HE4 and CA125 serum levels will be evaluated in this study for their ability to stratify patients presenting with a pelvic mass into risk groups with low, intermediate or high probabilities of harboring an ovarian cancer at the time of initial presentation. The algorithm using these two serum markers to stratify patients that was developed using pilot study data will be evaluated in this prospective multicenter pelvic mass study. We will also evaluate the inclusion of additional biomarkers and risk factors, such as ultrasound score, age, and menopausal status, into the algorithm to see if there is any improvement in the stratification of patients into the risk groups.